Set MDIO bus clock frequency and allow setting a custom maximum
frequency from device tree.
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Tested-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: Daniel Golle <daniel@makrotopia.org>
---
drivers/net/ethernet/mediatek/mtk_eth_soc.c | 21 +++++++++++++++++++++
drivers/net/ethernet/mediatek/mtk_eth_soc.h | 7 +++++++
2 files changed, 28 insertions(+)
@@ -764,8 +764,10 @@ static const struct phylink_mac_ops mtk_phylink_ops = {
static int mtk_mdio_init(struct mtk_eth *eth)
{
+ unsigned int max_clk = 2500000, divider;
struct device_node *mii_np;
int ret;
+ u32 val;
mii_np = of_get_child_by_name(eth->dev->of_node, "mdio-bus");
if (!mii_np) {
@@ -793,6 +795,25 @@ static int mtk_mdio_init(struct mtk_eth *eth)
eth->mii_bus->parent = eth->dev;
snprintf(eth->mii_bus->id, MII_BUS_ID_SIZE, "%pOFn", mii_np);
+
+ if (!of_property_read_u32(mii_np, "clock-frequency", &val)) {
+ if (val > MDC_MAX_FREQ || val < MDC_MAX_FREQ / MDC_MAX_DIVIDER) {
+ dev_err(eth->dev, "MDIO clock frequency out of range");
+ ret = -EINVAL;
+ goto err_put_node;
+ }
+ max_clk = val;
+ }
+ divider = min_t(unsigned int, DIV_ROUND_UP(MDC_MAX_FREQ, max_clk), 63);
+
+ /* Configure MDC Divider */
+ val = mtk_r32(eth, MTK_PPSC);
+ val &= ~PPSC_MDC_CFG;
+ val |= FIELD_PREP(PPSC_MDC_CFG, divider) | PPSC_MDC_TURBO;
+ mtk_w32(eth, val, MTK_PPSC);
+
+ dev_dbg(eth->dev, "MDC is running on %d Hz\n", MDC_MAX_FREQ / divider);
+
ret = of_mdiobus_register(eth->mii_bus, mii_np);
err_put_node:
@@ -363,6 +363,13 @@
#define RX_DMA_VTAG_V2 BIT(0)
#define RX_DMA_L4_VALID_V2 BIT(2)
+/* PHY Polling and SMI Master Control registers */
+#define MTK_PPSC 0x10000
+#define PPSC_MDC_CFG GENMASK(29, 24)
+#define PPSC_MDC_TURBO BIT(20)
+#define MDC_MAX_FREQ 25000000
+#define MDC_MAX_DIVIDER 63
+
/* PHY Indirect Access Control registers */
#define MTK_PHY_IAC 0x10004
#define PHY_IAC_ACCESS BIT(31)